-/* -*-c-*-
- *
- * $Id: pkcs1.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
- *
- * PKCS#1 1.5 packing
- *
- * (c) 2000 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <string.h>
-
-#include <mLib/bits.h>
-#include <mLib/dstr.h>
-
-#include "ct.h"
-#include "grand.h"
-#include "rsa.h"
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @pkcs1_cryptencode@ --- *
- *
- * Arguments: @mp *d@ = where to put the answer
- * @const void *m@ = pointer to message data
- * @size_t msz@ = size of message data
- * @octet *b@ = spare buffer
- * @size_t sz@ = size of the buffer (big enough)
- * @unsigned long nbits@ = length of bits of @n@
- * @void *p@ = pointer to PKCS1 parameter block
- *
- * Returns: The encoded result, or null.
- *
- * Use: Implements the operation @EME-PKCS1-V1_5-ENCODE@, as defined
- * in PKCS#1 v. 2.0 (RFC2437).
- */
-
-mp *pkcs1_cryptencode(mp *d, const void *m, size_t msz, octet *b, size_t sz,
- unsigned long nbits, void *p)
-{
- pkcs1 *pp = p;
- grand *r = pp->r;
- octet *q;
- size_t i, n;
-
- /* --- Ensure that the buffer is sensibly sized --- */
-
- if (pp->epsz + msz + 11 > sz)
- return (0);
-
- /* --- Allocate the buffer and fill it in --- */
-
- q = b;
- *q++ = 0x00;
- *q++ = 0x02;
- n = sz - msz - pp->epsz - 3;
- GR_FILL(r, q, n);
- for (i = 0; i < n; i++) {
- if (*q == 0)
- *q = r->ops->range(r, 255) + 1;
- q++;
- }
- *q++ = 0;
- if (pp->ep) {
- memcpy(q, pp->ep, pp->epsz);
- q += pp->epsz;
- }
- memcpy(q, m, msz);
- q += msz;
- assert(q == b + sz);
-
- /* --- Collect the result --- */
-
- return (mp_loadb(d, b, sz));
-}
-
-/* --- @pkcs1_cryptdecode@ --- *
- *
- * Arguments: @mp *m@ = the decrypted message
- * @octet *b@ = pointer to a buffer to work in
- * @size_t sz@ = the size of the buffer (big enough)
- * @unsigned long nbits@ = the number of bits in @n@
- * @void *p@ = pointer to PKCS1 parameter block
- *
- * Returns: The length of the output string if successful, negative on
- * failure.
- *
- * Use: Implements the operation @EME-PKCS1-V1_5-DECODE@, as defined
- * in PKCS#1 v. 2.0 (RFC2437).
- */
-
-int pkcs1_cryptdecode(mp *m, octet *b, size_t sz,
- unsigned long nbits, void *p)
-{
- pkcs1 *pp = p;
- const octet *q, *qq;
- size_t n, i;
- uint32 goodp = 1;
-
- /* --- Check the size of the block looks sane --- */
-
- if (pp->epsz + 11 > sz) /* OK: independent of ciphertext */
- return (-1);
- mp_storeb(m, b, sz);
- q = b;
- qq = q + sz;
-
- /* --- Ensure that the block looks OK --- */
-
- goodp &= ct_inteq(*q++, 0);
- goodp &= ct_inteq(*q++, 2);
-
- /* --- Check the nonzero padding --- */
-
- i = 0;
- while (*q != 0 && q < qq)
- i++, q++;
- goodp &= ct_intle(8, i);
- goodp &= ~ct_intle(qq - q, pp->epsz + 1);
- q++;
-
- /* --- Check the encoding parameters --- */
-
- if (pp->ep)
- goodp &= ct_memeq(b + ct_pick(goodp, 0, q - b), pp->ep, pp->epsz);
- q += pp->epsz;
-
- /* --- Done --- */
-
- n = qq - q;
- memmove(b, b + ct_pick(goodp, 1, q - b), n);
- return (goodp ? n : -1);
-}
-
-/* --- @pkcs1_sigencode@ --- *
- *
- * Arguments: @mp *d@ = where to put the answer
- * @const void *m@ = pointer to message data
- * @size_t msz@ = size of message data
- * @octet *b@ = spare buffer
- * @size_t sz@ = size of the buffer (big enough)
- * @unsigned long nbits@ = length of bits of @n@
- * @void *p@ = pointer to PKCS1 parameter block
- *
- * Returns: The encoded message representative, or null.
- *
- * Use: Implements the operation @EMSA-PKCS1-V1_5-ENCODE@, as defined
- * in PKCS#1 v. 2.0 (RFC2437).
- */
-
-mp *pkcs1_sigencode(mp *d, const void *m, size_t msz, octet *b, size_t sz,
- unsigned long nbits, void *p)
-{
- pkcs1 *pp = p;
- octet *q;
- size_t n;
-
- /* --- Ensure that the buffer is sensibly sized --- */
-
- if (pp->epsz + msz + 11 > sz)
- return (0);
-
- /* --- Fill in the buffer --- */
-
- q = b;
- *q++ = 0x00;
- *q++ = 0x01;
- n = sz - msz - pp->epsz - 3;
- memset(q, 0xff, n);
- q += n;
- *q++ = 0;
- if (pp->ep) {
- memcpy(q, pp->ep, pp->epsz);
- q += pp->epsz;
- }
- memcpy(q, m, msz);
- q += msz;
- assert(q == b + sz);
- return (mp_loadb(d, b, sz));
-}
-
-/* --- @pkcs1_sigdecode@ --- *
- *
- * Arguments: @mp *s@ = the message representative
- * @const void *m@ = the original message, or null (ignored)
- * @size_t msz@ = the message size (ignored)
- * @octet *b@ = a scratch buffer
- * @size_t sz@ = size of the buffer (large enough)
- * @unsigned long nbits@ = number of bits in @n@
- * @void *p@ = pointer to PKCS1 parameters
- *
- * Returns: The length of the output string if successful, negative on
- * failure.
- *
- * Use: Implements the operation @EMSA-PKCS1-V1_5-DECODE@, as defined
- * in PKCS#1 v. 2.0 (RFC2437).
- */
-
-int pkcs1_sigdecode(mp *s, const void *m, size_t msz, octet *b, size_t sz,
- unsigned long nbits, void *p)
-{
- pkcs1 *pp = p;
- const octet *q, *qq;
- size_t i, n;
-
- /* --- Check the size of the block looks sane --- */
-
- if (pp->epsz + 10 > sz)
- return (-1);
- mp_storeb(s, b, sz);
- q = b;
- qq = q + sz;
-
- /* --- Ensure that the block looks OK --- */
-
- if (*q++ != 0x00 || *q++ != 0x01)
- return (-1);
-
- /* --- Check the padding --- */
-
- i = 0;
- while (*q == 0xff && q < qq)
- i++, q++;
- if (i < 8 || qq - q < pp->epsz + 1 || *q++ != 0)
- return (-1);
-
- /* --- Check the encoding parameters --- */
-
- if (pp->ep && memcmp(q, pp->ep, pp->epsz) != 0)
- return (-1);
- q += pp->epsz;
-
- /* --- Done --- */
-
- n = qq - q;
- memmove(b, q, n);
- return (n);
-}
-
-/*----- That's all, folks -------------------------------------------------*/